A Valve adjustment oddity

[dan filipi]

If your following the Knocking Thread you'll know that I installed a 1200 cam in the left side.

Well with this cam I get what I consider an excessive amount of lifter clatter right around 3500 rpm.

I went and did another check and adjustment of the lash and found they were spot on at TDC per the book.

Keep in mind that we are finding out these cams get pretty beat up but also that these 1200 cams are in VERY good condition and appear to have low miles.

What I did was hold the feeler gauge against the tappet and valve stem as I rotated the engine slowly.
I found on one valve I could slip the feeler in easier before TDC but got tight to the proper adjustment at TDC.

Curious I went back around and made the adjustment at the point it got looser and the clatter is reduced quite a bit.

So what is going on here?
Considering this cam is in good condition and within spec, am I looking at a problem not with the cam but maybe with the rocker?

 

[joedrum]

dan it could be rocker shaft wear and the rocker too ...its unreasonable to think that the wear and problems are confined to the cams only .....fact is everything were seeing indicates full heads redo and mod to be tougher .....theres no telling how bad the seats might be also ....i figure out this way to change the cams out without taking the heads off and it was a good plan on my bike .....but between my work and observation of the noise level drop from trueing up the cams has led to this whole situation of poor performing heads......and engine noise....

that sounds like the springs have wore into the head enough and rocker into shafts enough to loose the minimin spring hieght and loose tension ...that adjustment you made was good .....but this is confromatipm to the points ive been making about why we need new springs and shims to bring back proper hieghts and spring pressure..... :mrgreen:

 

[dan filipi]

Makes sense that if the cams are worn then everything else would also be worn, at least to some extent.

Without having the heads totally redone with scrutiny by a pro shop we're pretty much left with what tools and abilities we can put together.
I'm sure the cams are bad and have to be done. That's one step I'll take.
I have a call in to the shop for a cost.
Now after measuring the loose springs I have on the shelf it's looking like I should get springs also as a minimum.
One inner spring is right at tolerance.

I'm still not sure though why with a known good cam why just one tappet adjustment had to be made to get into spec. and why just before TDC. The rocker looks very good to my neked eye and the head shop.
I'd understand why if this 1200 cam was worn like the others with what feels like a dip between TDC and the bottom, but it's not like that.

Just trying to cover all bases and be as detailed and careful as possible to do this right.
I want to avoid having a 1000 cam ground then find out they should have done the journals or something else or maybe the grind ended up being a waste of money for other reasons.

 

[joedrum]

can you imagine what that would be like if the cam was one of those rough ones like whats in the bike now on the other side.... :smilie_happy: :smilie_happy: :smilie_happy:

 

[dan filipi]

can you imagine what that would be like if the cam was one of those rough ones like whats in the bike now on the other side.... :smilie_happy: :smilie_happy: :smilie_happy:

Would be nice if it turns out to be that simple!!

 

[AApple]

Silly kweschum here, but...
Are the valve adjustments for the 1100 and the 1200 engines the same?

 

[dan filipi]

The 1200 has self adjusting lifters so how would we determIne that?

 

[AApple]

"Self Adjusting"? What...they have little elves that run around under the valve cover at night making adjustments? :smilie_happy:

"Self adjusting" to me means that it is a hydraulic cam. The specs for a hydraulic are different than a solid cam.....something stinks in Denmark.... :headscratch:

Hydraulic cams can use a different ramp angle to open the valves quicker, since they have the cushioning effects of the lifter. In automotive applications, it's never a good thing to mix-match the different cams/lifters. The designs are just totally different, which means the end results are also....

 

[dan filipi]

The way the adjuster works is the pin the rocker is on is sort of out of round.
The adjuster rotates that pin to take up lash.
Basically the adjuster is moving the center of the rocker to take up lash and does nothing to move the follower or valve end of the rocker like conventional push rod hydraulics.
Very clever design with what I know.

Since they work this way I'd think we're not really mixing and matching hydraulic with mechanical "lifter" because it's not really a different lifter mechanism.

 

[AApple]

:headscratch: :headscratch: :headscratch:
So....there's no spec for adjusting the valves like there is on the 1000-1100s?
Dang..yer gonna make me go to the Gallery and look in da service manual... :read: I gotta see how this is set up.

 

[mike in idaho]

Started my '79/1100 project bike the other day just to see if it would run. I had done a valve job on this old engine and wanted to see if the junk carburetor set I had was in good enough shape to even start it. Twenty minutes of fiddling(and a battery charger) and it was going. It ran pretty well for about 10 minutes before I shut it off, I thought it it had a little bit of valve noise but I wasn't really sure(open headers, no mufflers). Apparently I had forgotten to adjust the valves (I had intended to do it after the engine was installed) the lock nuts had been left loose and five of the adjusters had backed out of the rockers and were just lying in the covers. No harm done and no parts lost in the sump. It's surprising how well it ran with some of the valves having nearly a quarter inch of tappet clearance. The valves have been adjusted (and the lock nuts tight) it should run better yet now.

 

[joedrum]

thats funny :smilie_happy: :smilie_happy: :smilie_happy: better than broken parts you must be living right... :heat: :mrgreen:

 

[gingerbreadman]

dan filipi » Wed Dec 15, 2010 11:19 am[/url]":392lavz1]
The 1200 has self adjusting lifters so how would we determIne that?

Uhuh! Yer words not mine, Dan me boy!